WO2001022234A1

WO2001022234A1 - Method and system for multicast data communication to distribute internet web content data to a plurality of server computers using geostationary satellite

Info

Publication number: WO2001022234A1
Application number: PCT/JP2000/006329
Authority: WO
Inventors: David Wuertele; Noriyoshi Yamazaki; Miharu Jimbo; Kazuhiko Oho; Hiroyuki Hanasaka; Ryuichi Hanaoka; Kouji Nakamura; Hiroshi Uchiyama
Original assignee: Internet Research Institute, Inc.; Direct Internet Co., Ltd.
Priority date: 1999-09-17
Filing date: 2000-09-14
Publication date: 2001-03-29
Also published as: JP2001092745A

Abstract

A communication system comprises a plurality of systems connected by a geostationary satellite and provides high-speed, high-efficient transmission of content data. A transmission system has a distribution URL list that is a list of the content data on the WEB, which are to be distributed to receiver systems. When the transmission system has received new content data in the distribution URL list from the WEB, the content data are sent by multicast communication using the geostationary satellite to update cache at the receiver systems.

Description

Specification

Communication system and method for delivering multicast data of internet content data to a plurality of server computers using geosynchronous satellites

TECHNICAL FIELD The present invention relates to a communication system and a method for updating content data on the Internet web between a number of server computers, and particularly to a method for updating specific content data on the Internet web to a number of servers. In order to share the data with the cache server at one server, one server computer sends a new data content related to the new web to many other server computers at a point-by-point multi-point transmission. A communication system and a method for caching a cache server.

BACKGROUND ART When downloading web content data via the Internet, first, a client computer accesses a server computer which manages the client computer as one of the clients. The server computer may be, for example, a server combination of an Internet service provider or a server computer of a local area network, an intranet or an extranet. And this ku Based on a request from a client computer to access the website, the server computer connects directly or indirectly to the server computer on the network that owns and manages the target website. In many cases, the connection is made to the target server computer via many other network server computers. When access to the server computer that owns and manages the target website is granted by the server computer, the server computer receives a download request from the client computer and permits download. After determining whether or not to do so, the requested web content data is downloaded only if down-logging is allowed. That is, the web content data is transmitted directly or indirectly from the server computer that has permitted the down port to the server computer that manages the client computer that has issued the down port request. In many cases, it is transmitted to the server computer that manages the client computer that has issued the download request via a number of other intermediate network server computers. However, as the Internet society evolves, the amount of data managed on websites is increasing at a rapid pace, and not only is the frequency of access to the website increased, but of course the total frequency of downloads is increased. To increase. In addition, the number of websites on the Internet is exploding. Under these circumstances, serious problems faced by the Internet society include hardware equipment for smoothly transmitting a huge amount of communication data and reduction of costs for the communication. For example, as described above, when downloading web content data from a web site on the Internet, not only text data such as characters, but also data such as still images, moving images, audio data, music data, and / or The frequency of downloading various software is becoming very high. The data and software other than the text data are very large. Access to the target website and demands for down-links are very small because the data volume is very small. Although it does not matter, content data often includes not only text data such as characters, but also data such as still images, moving images, audio data, music data, and various types of software. Becomes In other words, when data is transmitted from a client computer to a server computer, the above-mentioned problem does not occur. Conversely, when data is transmitted from a server computer to a client computer, expansion of communication hardware equipment and its communication are performed. How to solve the two issues of cost reduction is the most important for further developing the Internet society. Currently, the communication hardware of INN Yuichi Net is terrestrial and submarine communication cables (communication lines), and their data transmission speed, that is, the amount of data that can be transmitted per unit time, is limited. A large number of client requests on the site come from a huge number of client computers managed by server computers around the world via the Internet. In the communication system currently used, each time a download request is received from each client, the data is transmitted over the Internet to the server computer that manages the client. The server computer that manages this client and the server computer that has the website for download are not always directly connected, and often connected via one or more other server computers. Therefore, every time there is a download request from a client, the data is transmitted via the Internet until the server convenience that manages each client independently. For example, even if 100,000 people request to download the same content, the current system sends 100,000 times the same content independently for each request. Inefficient. In addition, in most cases, the server computer on which the target website is located and the client computer that requested the download are indirectly connected via many other server computers on the Internet, and the data to be downloaded is composed of characters. In addition to text data such as, still images, moving images, When data such as voice data and music data or various software is included, the inefficiency of the communication method becomes extremely remarkable, and the increase in communication time and communication cost becomes extremely large. Most Internet service providers bear the cost of communicating with server computers connected via the Internet, and clients are required to communicate between their respective Internet service providers and each client. It is currently paying for the costs. Under such circumstances, in order to solve the above-mentioned problem using existing technology, it is conceivable to change all of the current ground and submarine communication lines to high-speed lines such as optical fibers. In this case, it is necessary to change all communication lines connecting each server computer on the Internet, and it is also desirable to change the communication lines between the client and the server computer. However, as a practical matter, changing all of the currently used analog lines to high-speed communication lines such as optical fibers requires enormous costs. In the near future, it is expected that Internet service providers will install server computers in almost every region of the globe, and it will be necessary to extend communication networks throughout the inland continent. It is very difficult to realize such a true Internet society on a global scale using only the existing communication technology of Inyuichi Net. Under these circumstances, in order to solve the above-mentioned difficult problems and achieve the above-mentioned object, a new communication system and communication method completely different from the technology currently used for data transmission on the Internet. Is required. Therefore, an object of the present invention is to provide a novel communication system and a new communication method that can solve the above-mentioned problems. It is a further object of the present invention to enable ultra-high-speed and high-efficiency Internet content data transmission, and in particular, it is possible to download web contents having a huge amount of data in a very short time even if a large number of requests occur simultaneously. And super fast and The aim is to provide a communication system and communication method that can sufficiently respond to the next century's Internet network without expanding the current land line and submarine line by transmitting data at high efficiency. I do.

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention provides: (1) a geostationary satellite having a fixed area that can be distributed overnight; and (2) an internet station installed in the fixed area of the geostationary satellite, and (3) at least one of the server computers has a cache server for owning and managing the content of the web site and having a cache server for caching the cache data; Means for transmitting the latest web content data received from the client to the geostationary satellite; (4) means for receiving the latest web content data of another server computer distributed from the geostationary satellite; and (5) means for transmitting the web content data. Means for storing an editable distribution URL list in which at least one URL that needs to be distributed is listed; A communication system that distributes a new content data relating to the web of a certain server computer transmitted by the transmission means to another server computer via a multicast-to-multipoint method by a point-to-multipoint method; However, based on at least one of the amount of data for the content data and a prediction of the frequency of access from the server computer to the server to download the content data, The system further includes means for enabling the distribution URL list to be edited. After new content data relating to the Web having the URL described in the distribution URL list as an address is generated, content data from the client is generated. Yes Regardless of whether or not none, the web content data of the URL described in this distribution URL list is transmitted to the geostationary satellite in advance, and the geostationary satellite transmits the URL to another server Multicast data delivery is performed by using the point-to-point multi-point method in the evening, and the transmitted data is cached in the cache server of each server computer. Provided is a communication system characterized in that when a download request is issued, the client can be directly downloaded from a cache server of a server computer to which the client belongs. Further, according to the present invention, (1) a geostationary satellite having a fixed area to which data can be distributed, and (2) a content data of a web which is installed in the fixed area of the geostationary satellite and is in-net-net. A plurality of different server computers having a cache server for owning and managing and for performing a cache

(3) At least one communication system management server computer connected to the server computer via the Internet is further provided, and at least this communication system management server computer needs to distribute web content data. It has means for storing and managing an editable distribution URL list in which one URL is listed, and obtains the latest content data of the web relating to the URL described in this distribution URL list from the server computer and obtains a geostationary satellite. A communication system management server computer having means for transmitting to the

(4) means for receiving the latest content data of the web of another server computer distributed from the geostationary satellite, provided for each server computer, wherein the geostationary satellite is transmitted by the transmitting means. In a communication system in which new content data related to a web of a certain server computer is distributed to another server computer by multicasting in a point-by-point multi-point manner, at least one of the server computers distributes from the geostationary satellite. The communication system management server computer further includes means for sending a reception report to the effect that the received web content data has not been completely received to the communication system management server computer. Complete web content data To the server computer that has not received There is provided a communication system further comprising means for transmitting data not received. Further, according to the present invention, it is installed in a fixed area of a geostationary satellite having a fixed area to which data can be distributed, and owns and manages content data of the web of the Internet, and caches cache data. The latest web content data received from individual clients of a plurality of different server computers having a cache server for transmission to other server computers via the geostationary satellite is transmitted in a point-to-multipoint manner using multicast data. In the communication method for performing distribution, a data amount for content data and / or a prediction on an access frequency from a client of the server computer to the web for downloading the content data are based on at least one of the following. Web content By editing at least one distribution URL list that needs to distribute the content, new content data relating to the Web having the URL described in the distribution URL list as an address is generated, and then the content data is downloaded from the client. Regardless of the presence or absence of the request, the web content data of the URL described in the distribution URL list is transmitted to the geostationary satellite in advance, multicast data is distributed, and the transmitted data is transmitted to each server computer. By causing the cache to be cached in the cache server, when a request to download content data is subsequently generated from a client of each server computer, a direct download is performed from the cache server of the server console to which this client belongs. That it is possible to Providing a communication method characterized. The current communication hardware on the Internet is ground and undersea communication cables (communication lines), and the data transmission speed, that is, the amount of data that can be transmitted per unit time, is limited. However, according to the present invention, the content outlet Regardless of whether or not there is a request from the server, the web content data of the URL described in the distribution URL list is transmitted to the geostationary satellite in advance, and multicast data is distributed to each server computer by the point-to-multipoint method. Then, the distributed data is cached in the cache server of each server computer, so that when a client of each server computer requests a download of the content overnight, the client belongs to the server. It is now possible to download directly from the cache server on the server computer. For example, a large number of download requests for popular websites are received via the Internet from a huge number of client computers managed by server computers around the world. However, in the communication system according to the present invention, before receiving a download request from each client, the web content data of the URL described in the distribution URL list is transmitted to the geostationary satellite in advance, and the point-to-multipoint method is used. Multicast data is distributed to each server computer, and this distributed data is cached in the cache server of each server computer. Therefore, each client simply receives the data directly from the cache server of the server computer to which this client belongs. Just download. For this reason, as in the past, for each download request, independently from the server computer that has the website for download to the server computer that manages the client who requested the down-link, the Internet There is no need to send data via. The server computer that manages this client and the server computer that has the website for download are not always connected directly, but are often connected via one or more other server computers. Therefore, when the communication system and the communication method of the present invention are used, the multicast data is distributed to each server computer by the point-to-multipoint method using the geostationary satellite, so that each server computer is transmitted. Evening ground and seabed communications Regardless of the network structure of the network and the capacity of the communication line, etc., ultra-high-speed and highly efficient data distribution is possible. Further, since the distributed data is cached in the cache server of each server computer, each client may simply download the data directly from the cache server of the server computer to which the client belongs. In other words, there is no need to send data via the Internet network to the server computer that independently manages each client every time there is a download request from the client. For example, even if 100,000 people request the same content to be downloaded, the current system transmits data of the same content 100,000 times independently for each request. Very inefficient. However, according to the communication method and the communication system of the present invention, before receiving a download request from each client, the web content data of the URL described in the distribution URL list is transmitted to the stationary satellite, Since multicast data is distributed to each server combination by the point-to-multipoint method, no matter how much the number of download requests increases, the speed and efficiency of data distribution between server computers are not affected at all. The distributed data is cached in the cache server of each server computer, and each client simply downloads the data directly from the cache server of the server computer to which the client belongs, thus increasing the number of download requests. Since the amount of local communication between the client computer and the server computer to which the client computer belongs only increases, the capacity and capacity of communication equipment such as communication lines directly connecting the server computer having the target web site are reduced. No more worrying about exceeding. As the data to be downloaded includes not only text data such as characters, but also data such as still images, moving images, audio data, music data, or various software, the communication system and communication of the present invention are more likely to be included. By using the method The advantages of improving communication speed and communication efficiency become remarkable, and the effect of reducing communication time and communication cost becomes extremely large. Most of the Internet service providers are responsible for the cost of communication with server computers connected via Internet, and clients are required to communicate with their respective Internet service providers. Even in view of the current cost of communication between clients, the significant reduction in the time required for data communication between server computers by using the communication system and communication method of the present invention can be achieved by Internet service providers. This will lead to a significant reduction in communication costs incurred. As described above, since the multicast data is distributed to each server computer by the point-to-multipoint method using the geostationary satellite, enormous and high-speed data distribution between each server computer is required on the ground and under the sea. Do not use existing communication lines. Therefore, it is possible to respond sufficiently without expanding existing ground and submarine communication lines. In other words, there is no need to convert all current terrestrial and submarine communication lines to high-speed lines such as optical fibers, and there is no need for enormous costs. In the near future, it is expected that the Internet Service Provider will install server computers in almost all areas of the earth, but using geostationary satellites, a point-to-multipoint system will be used. In order to deliver multicast data to server computers, there is no need to set up a communication network all over the inland continent, and to realize such a full-scale Internet society on a global scale, It can be understood that the communication system and the communication method of the present invention are extremely suitable. That is, the communication system and communication method of the present invention are novel communication systems and communication methods that can solve all of the above problems, and enable ultra-high-speed and high-efficiency Internet content data transmission. In particular, there are many and simultaneous requests for downloading web content with huge data volume. Even in a very short time, by transmitting data at extremely high speed and high efficiency, we will provide communication equipment that can fully respond to the Internet society of the next century without expanding the current land line and submarine line at all. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall configuration diagram of a communication system according to the present invention for distributing multicast data to a plurality of server computers by using a geosynchronous satellite according to the present invention. FIG. 2 is a protocol layer configuration diagram of a communication system for performing multicast data distribution of Internet web content data to a plurality of server computers using a geostationary satellite according to the present invention. FIG. 3 is an overall configuration diagram of a communication system according to the present invention. FIG. 4 is a configuration diagram of a web patrol robot of the communication system according to the present invention. FIG. 5 is a further configuration diagram of a web patrol robot of the communication system according to the present invention. FIG. 6 is a configuration diagram of satellite IP multicast of the communication system according to the present invention. FIG. 7 is a configuration diagram of web push of the communication system according to the present invention. FIG. 8 is a process configuration diagram of web push of the communication system according to the present invention. FIG. 9 is a diagram showing a satellite receiving step of the communication system according to the present invention. FIG. 10 is a configuration diagram of an ICP server of the communication system according to the present invention. FIG. 11 is a diagram of measures for improving the reliability of the communication system according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. According to the present invention, (1) a geostationary satellite having a fixed area in which data can be distributed, and (2) owning and managing content data of an internet web installed in the fixed area of the geostationary satellite, And a plurality of different server computers each having a cache server for caching the cache data; and (3) means for at least one of the server computers transmitting the latest web content data received from the client to a geostationary satellite. (4) means for receiving the latest content data of the web of another server computer transmitted from the geostationary satellite, and (5) an editable listing at least one URL which needs to distribute the web content data. Means for storing a distribution URL list, wherein the geostationary satellite is transmitted by the transmitting means. In a communication system that distributes new content data related to a web of a certain server computer to another server computer in a multicast manner by a multi-point method, the communication system includes: Compiling the distribution URL list based on at least one of a prediction on the frequency of access from the server computer to the web to download the content data; By further providing a means for enabling, after the generation of new content data relating to the Web having the URL described in the distribution URL list as an address, the presence or absence of a request for a down-loading of the content data from the client. Regardless of this in advance The web content data of the URL described in the distribution URL list is transmitted to the geostationary satellite, and the geostationary satellite distributes the multicast data to another server computer by the point-to-multipoint method, and transmits the transmitted data. Data is cached in the cache server of each server computer, and when a client of each server computer subsequently requests a download of the content data, it is downloaded directly from the cache server of the server computer to which this client belongs. A communication system characterized in that the communication system is configured to be able to do so. As described above, the provision of this system allows the web server to use a geostationary satellite to predict the high hit rate of web content data and large amounts of content data beforehand to the cache server via the satellite Internet. By sending it, it became possible to provide high-speed web access privileges without affecting the terrestrial line. In other words, regardless of whether or not there is a request to download content data from the client, the web content of the URL described in the distribution URL list is transmitted to the geostationary satellite in advance, and the point-to-multipoint method is used. Multicast data is distributed to each server computer, and the distributed data is cached in the cache server of each server computer. After that, a request for downloading content data is generated from a client of each server computer. When this happens, it is possible to download directly from the server to which this client belongs. In the communication system according to the present invention, before receiving a download request from each client, the web content data of the URL described in the distribution URL list is transmitted to the geostationary satellite in advance, and each of the servers is transmitted by the point-to-multipoint method. Multicast data is distributed to the computer, and the distributed data is cached in the cache server of each server computer. Therefore, each client simply downloads the data directly from the cache server of the server computer to which this client belongs. Just do it. For this reason, as before, websites intended for download are independent of each download request There is no need to send data over the Internet from a certain server computer to a server computer that manages clients who have requested a down-link. The server computer that manages this client and the server computer that has the website for download are not always directly connected, but are often connected via one or more other server computers. However, when the communication system and the communication method of the present invention are used, multicast data is distributed to each server computer by a point-to-multipoint system using a geostationary satellite, so that the ground and the sea floor connecting the server computers are connected. Ultra-high-speed and highly-efficient data distribution is possible regardless of the network structure of the communication network or the capacity of communication lines. Further, since the distributed data is cached in the cache server of each server computer, each client can simply download the data directly from the cache server of the server computer to which the client belongs. In other words, there is no need to send data via the Internet to the server computer that independently manages each client every time there is a download request from the client. The use of the communication system and the communication method of the present invention makes it possible to greatly reduce the time required for data communication in the evening, which significantly increases the communication cost incurred by the Internet service provider. Leads to significant reductions. As described above, since multicast data is distributed to each server computer by the point-to-multipoint method using the geostationary satellite, enormous and high-speed data distribution between each server computer is required on the ground and on the sea floor. Do not use existing communication lines. Therefore, it is possible to respond sufficiently without expanding existing ground and submarine communication lines. Hereinafter, preferred modifications of the communication system according to the present invention will be described. A plurality of server computers, for example, all of which are distributed from geostationary satellites Means for receiving the latest content data of the web of the server computer and storing the received latest content data in the cache server, and at least one of the server computers quiesces the latest content data of the web received from the client; It is preferable to have means for transmitting to the satellite. This makes it possible to achieve the above-described effect. Furthermore, it is preferable that a plurality of, for example, all of the server computers have means for transmitting to a geostationary satellite. This makes it possible to achieve the above-described effects. A plurality of the server computers, for example, all have a means for receiving the latest content data on the web of another server computer distributed from a geostationary satellite and storing the received latest content data in a cache server; And at least one communication system management server computer connected by the Internet and the Internet, and the communication system management server computer manages the distribution URL list, and a web page related to the URL described in the distribution URL list. It is also preferable to have means for obtaining the latest content data from the server computer and transmitting it to a geostationary satellite. This makes it possible to provide the above-described operation. The means for acquiring the latest content data possessed by the communication system management server computer and transmitting the latest content data to the geostationary satellite includes a patrol that periodically traverses the URLs described in the distribution URL list and automatically collects the latest content data from the server computer. · It can consist of automatic collection means and means for transmitting the latest contents data to geostationary satellites. By enabling automatic collection, it is possible to collect data at high speed without spending any money on human resources. The patrol / automatic collecting means comprises web patrol application software constructed in the application layer, while the means for transmitting the latest content data to the geostationary satellite comprises a multicast transmission line constructed in the presentation layer. Library. Since the automatic collection means is built in the application layer, it is easy to create a collection means program and change the design. The presence of the satellite transmission means in the presentation layer facilitates the conversion of data representation. The web patrol application software may be activated as a daemon and continue to run until system shutdown. By continuing to start as a daemon, it is possible to keep it running at all times, and process monitoring becomes easier. Each server computer consists of web push software built on the application layer for caching in the cache server, and a multicast reception library built on the presentation layer as a means to receive the latest content data on the web. May have. Since the web push software is built on the application layer, it is easy to create a web push software program and change its design. The presence of the multicast reception library in the presentation layer facilitates the conversion of data representation. The web push software may be activated as a daemon and continue to run until system shutdown. By continuing to start as a daemon, it is possible to keep it running at all times, and it is easy to monitor processes. The communication system management server computer has a duplex configuration including a master system and a slave system. A monitoring means provided in the slave system monitors a process status table provided in the master system by a timer, and a failure occurs in the master system. When the occurrence is found or when the slave cannot communicate with the master, the monitoring means may shut down the master and activate the patrol / automatic collection means in the slave. By adopting a duplex configuration, the possibility of the system being shut down is greatly reduced, and system reliability is improved. By further providing a common server computer that is connected to the master system and the slave system and that owns and manages the distribution URL list, the master system is shut down, and the slave system goes round. When activating the automatic collection means, it may be possible to perform a patrol based on the distribution URL list. Even when the main system stops, the distribution work does not stop by patrol without stopping the system, and the reliability is further improved. At least one of the server computers, and preferably all of the server computers, receives, via the Internet, a reception report indicating that the web content data distributed from the geostationary satellite was not completely received by the communication system. The system further comprises means for sending to the management server computer, and the communication system management server computer transmits the data not received to the server computer which has not completely received the web content data based on the reception report. It may further have means for transmitting via the Internet. Having this means enabled error recovery, and established a method for the receiving side to receive data more reliably. At least one of the server computers, and preferably all of the server computers, receive, via the Internet, a reception report indicating that the web content data transmitted from the geostationary satellite was not completely received. The system further comprises means for sending to the system management server computer, and the communication system management server computer further comprises means for transmitting again the data not received to the geostationary satellite based on the reception report. The geostationary satellite may deliver the data again overnight so that the server computer can completely receive the web content data. It will be possible to re-transmit the data overnight via geostationary satellites. The means for editing the editable distribution URL list may include collecting and analyzing information on the frequency of access to each web from the server computer client to determine a URL to be included in the distribution URL list. Even software that automatically collects and analyzes access frequency information Good. Judging based on access frequency, etc., there is no risk of leaking popular URLs. In addition, human costs and mistakes in creating distribution lists can be reduced, and accurate list creation can be performed quickly and in a short time. The software that automatically collects and analyzes the access frequency information obtains the access log information of each server computer and integrates this access log information to reflect the access frequency of each web on the Internet. May be software that determines a value to be written and determines a URL to be included in the distribution URL list based on a value reflecting the access frequency. By calculating the access frequency using the access log, it is possible to create a URL that actually reflects the popularity of the URL, which is highly effective in caching. The software for automatically collecting and analyzing the access frequency information is set in advance for each server computer in the value of the access frequency of each web on the Internet included in the access log information of each server computer. It may be software that calculates the weighted value, calculates an addition value or an arithmetic average of the weighted values, and determines a URL to be described in the distribution URL list. It is possible to reflect the editor's intention not only by simple access frequency but also by weighting. The software for automatically collecting and analyzing the access frequency information does not weight the access frequency value of each web on the Internet included in the access log information of each server computer. It may be software that calculates an addition value or an arithmetic average value and determines a URL to be described in the distribution URL list. It is possible to create a statistically processed list without the editor's subjective discretion. The means for editing the editable distribution URL list may be software for automatically editing the distribution URL list based only on the data amount for new content data. When targeting websites that can be downloaded by software, data, etc. with a large amount of data, web data with a large amount of data Has the effect of caching. The means for editing the editable distribution URL list collects at least one of a data amount for a new content data and information on a frequency of access to each web from a client of the server computer, and based on an operator's analysis, It may be software for determining a URL to be described in the distribution URL list and enabling the distribution URL list to be edited. The selection of URLs to be cached shall not only be automatically selected by software, but also shall allow manual editing by the user. The information determining means at that time is determined based on at least one of the data amount and the access frequency. The software collects both the amount of data for the new content data and the frequency of access to each web from the server computer client, and based on the analysis of the operator, the distribution URL It may be software for determining a URL to be described in the list and enabling the distribution URL list to be edited. The selection of URLs to be cached shall not only be made automatically by software, but shall also be possible for the user to manually edit. In addition, the information determining means at that time can make a more accurate determination by determining both from the data amount or the access frequency. The software collects both information on only the data amount of the new content data, determines a URL to be included in the distribution URL list based on an analysis of an operator, and edits the distribution URL list. It may be software for enabling the above. For sites that can download software, data, etc. with a large amount of data, it is effective to cache web data with a large amount of data, which takes a long time to download. In some cases, it is preferable to rely on human prediction, and by adding flexibility to the creation of the distribution URL list, it has become possible to cope with cases where it is impossible to make predictions using only past data statistics. The software collects both information relating only to prediction of access frequency, determines a URL to be included in the distribution URL list based on an analysis of an operator, and enables the distribution URL list to be edited. It may be a way. By making the URL selection basis based on the access frequency, it is possible to select a URL that is purely popular, and it is possible to make a judgment at the operator's discretion. URLs listed in the distribution URL list are linked to well-known portal sites predetermined by the operator, and include URLs of frequently accessed websites based on past Internet access information. But it is fine. Well-known portal sites are accessed frequently, and sites linked from those portal sites are necessarily accessed frequently. Therefore, including a well-known portal site includes URLs that are frequently accessed. The URL described in the distribution URL list may be a URL of a file containing at least one of software, image data, audio data, and music data whose data amount is larger than a certain standard predetermined by the operator. . Software, still and moving image data, audio data, and music data generally have larger data volumes than text. Therefore, caching more than a certain amount of data on each server in advance promises to greatly reduce download time. Although the circulating / sending means is a UR described in the distribution URL list, even if the content is not marked as cache enabled in the HTT P header, the content has been distributed by the communication system in the past, Content that has expired and whose last update date of the previously delivered content matches the last update date of the content that is currently being delivered may include selection / control software to prevent transmission to the geostationary satellite. . The removal of web content data that is banned or unnecessary for caching in advance This makes it possible to use limited memory resources effectively. The patrol / transmission means includes means for designating a URL distribution start time and enabling schedule distribution, and means for designating only the top page in the URL and collectively transmitting hyperlinked content within the same site. It may further include. By specifying the distribution start time, the data release time can be determined on the distribution side. Also, since the access frequency of the hyperlinked contents may increase at once, there is an effect that the contents are transmitted at once. The server computer has a plurality of clients, and the clients may include any type of server computer forming a closed network connected to the Internet via the server computer. Further, according to the present invention, (1) a geostationary satellite having a fixed area in which data can be distributed, and (2) a content server of the Internet installed in the fixed area of the geostationary satellite and connected to the Internet. A plurality of different server computers having a cache server for owning and managing

(3) At least one communication system management server computer connected to the server computer via the Internet is further provided, and at least one URL required for the communication system management server computer to distribute web content data is provided. Means for storing and managing the listed editable distribution URL list, and means for obtaining the latest content of the web relating to the URLs described in the distribution URL list from the server computer and transmitting the list to the geostationary satellite A communication system management server computer having

(4) a means provided for each server computer to receive the latest content of the web of another server computer distributed from the geostationary satellite; and the geostationary satellite is transmitted by the transmitting means. Communication system that distributes new content data related to the web of one server computer to another server computer by multicasting in a multi-point manner , At least one of the server computers further includes means for transmitting a reception report to the communication system management server computer to the effect that web content data distributed from the geostationary satellite has not been completely received. At the same time, the communication system management server computer further includes means for transmitting the data not received to the server computer which has not completely received the content data of the web based on the reception report. Is also good. Having this means enabled error recovery, and established a method for receiving data more reliably on the receiving side. As described above, the provision of this system allows web content data, which is predicted to have a high hit rate using geostationary satellites, and large content data to be transmitted to the cache server via the satellite Internet. By sending it with, it became possible to provide high-speed web access privileges without affecting the terrestrial line. In other words, regardless of whether or not there is a request from the client to download content data, the Web content data of the URL described in the distribution URL list is transmitted to the geostationary satellite in advance, and the point-to-multipoint method is used. Multicast data is distributed to each server computer, and this distributed data is cached in the cache server of each server computer. After that, the content data is distributed from the client of each server computer. When a request for a down-link of the server occurs, the server to which this client belongs can be downloaded directly from the evening cache server. In the communication system according to the present invention, the web content data of the URL described in the distribution URL list is transmitted to the geostationary satellite, and the multicast data is distributed to each server computer by the point-to-multipoint method. Each client is simply assigned to the server server to which this client belongs, because the data is cached in the cache server of each server computer. All you have to do is download them directly from the cache server of the computer. For this reason, as before, data is transmitted via the Internet from the server computer that has the website for download to the server computer that manages the client that requested the download, independently for each download request. No need to send. The server computer that manages this client and the server computer that has the website for download are not necessarily directly connected, and often through one or more other server computers. Although connected, when the communication system and the communication method of the present invention are used, multicast data is distributed to each server computer by a point-to-multipoint system using a geostationary satellite, so that each server computer is distributed. Ultra-high-speed and highly-efficient data distribution is possible regardless of the network structure of the ground and sea floor communication networks connecting them and the capacity of communication lines. Furthermore, since the distributed data is cached in the cache server of each server computer, each client can simply download the data directly from the cache server of the server computer to which the client belongs. That is, there is no need to transmit data via the Internet until a server computer that manages each client independently each time a download request is received from a client. The server communication by using the communication system and the communication method of the present invention makes it possible to greatly reduce the time required for overnight data communication, which greatly reduces the communication cost incurred by the Internet service provider. Leads to. As described above, since multicast data is distributed to each server computer by the point-to-multipoint method using the geostationary satellite, the huge and high-speed data distribution between each server computer requires the existing ground and sea floor. Do not use communication lines. Therefore, it is possible to respond sufficiently without expanding existing ground and submarine communication lines. Hereinafter, preferred modifications of the communication system according to the present invention will be described. The reception report is transmitted to the communication system management server computer via the Internet, and data not received by the server computer that has not completely received the web content data is received. It may be transmitted via the Internet. By retransmitting on the Internet, retransmission can be performed only to the retransmission target server, and transmission and reception are possible. The reception report is transmitted to the communication system management server computer via the Internet, and the communication system management server computer transmits data not received again to the geostationary satellite based on the reception report. The provision of the means may make it possible for the geostationary satellite to perform the data distribution again so that the server computer can completely receive the content data of the web. In particular, if there are a large number of servers that could not be received, it may be more efficient to collectively re-transmit via satellite rather than responding individually via the Internet. At that time, satellite retransmission is enabled. The communication system management server computer includes at least one of an amount of data for the content data and a prediction regarding the frequency of access from the client of the server computer to the web in order to download the content data. Based on the above, further comprising means for enabling the distribution URL list to be edited, after a new content data relating to the web having the URL described in the distribution URL list as an address, Regardless of whether there is a request to download content data from the client or not, the Web content data of the URL described in this distribution URL list is transmitted to the geostationary satellite in advance, and the geostationary satellite points to another server computer. · Two · Multi-point Perform cast data delivery, by caching the transmitted data in the key Yasshu server for each server computer, then the content from the client of each server computer When a data download request is issued, the data may be downloaded directly from the cache server of the server computer to which the client belongs. When content is updated, the updated content is immediately delivered, so that the latest data is always cached. The means for acquiring the latest content data of the communication system management server computer and transmitting the latest content data to the geostationary satellite, periodically traverses the URLs described in the distribution URL list, and automatically collects the latest content data from the server computer. Patrol · Automatic collection means and means for transmitting the latest content data to geostationary satellites may be provided. By conducting regular patrols, it is possible to always find the latest content easily. The patrol / automatic collection means comprises web patrol application software constructed on the application layer, while the means for transmitting the latest content data to the geostationary satellite comprises a multicast transmission library constructed on the presentation layer. You may. The presence of the satellite transmission means in the presentation layer facilitates the conversion of data representation. The web patrol application software may be activated as a daemon and continue to run until system shutdown. By continuing to start as a daemon, it is possible to keep it running at all times, and process monitoring becomes easier. Each server computer has web push software built on the application layer to cache in the cache server, and a multicast reception library built on the presentation layer as a means to receive the latest content data on the web. May have. By constructing the Web Push software on the application layer, it is easy to create and change the design of the Web Push software program. The presence of the multicast reception library in the presentation layer facilitates the conversion of data representation. The web push software may be activated as a demo and continue to run until the system shutdown. By continuing to start as a daemon, it is possible to keep it running at all times, and it is easy to monitor processes. The communication system management server computer has a duplex configuration including a master system and a slave system. A monitoring means provided in the slave system monitors a process status table provided in the master system by a timer, and a failure occurs in the master system. When the occurrence is detected or when the slave cannot communicate with the master, the monitoring means may shut down the master and activate the patrol / automatic collection means in the slave. The use of a duplex configuration greatly reduces the possibility of the system stopping, and improves the reliability of the system. By further providing a common server computer connected to the main system and the sub system and owning and managing the distribution URL list, the main system can be shut down and the subordinate system can start the automatic collection means. Alternatively, it may be possible to perform a tour based on the distribution URL list. Even when the main system stops, the distribution work does not stop by patrol without stopping the system, and the reliability is improved. The means for editing the editable distribution URL list may include collecting and analyzing information on the frequency of access to each web from the server computer client to determine a URL to be included in the distribution URL list. It may be software that automatically collects and analyzes access frequency information that enables it. Judging from access frequency, there is no danger of leaking popular URL. In addition, human costs and mistakes in creating distribution lists can be reduced, and lists can be created quickly and in a short time. The software that automatically collects and analyzes the access frequency information obtains the access log information of each server computer and integrates this access log information. Software that determines a value that reflects the frequency of access to each web on the Internet, and determines the URL to be included in the distribution URL list based on the value that reflects the frequency of access. . By calculating the access frequency using the access log, it is possible to create a URL that actually reflects the popularity of the URL, which is highly effective in caching. The software that automatically collects and analyzes the access frequency information preliminarily sets the value of the access frequency of each web on the Internet included in the access log information of each server computer for each server computer. It may be software that calculates the added weight or the arithmetic mean of the weighted values and determines the URL to be described in the distribution URL list. It is possible to reflect the editor's intention not only by simple access frequency but also by weighting. The software that automatically collects and analyzes the access frequency information is an addition value without weighting the access frequency value of each web on the Internet included in the access log information of each server computer. Alternatively, software for calculating an arithmetic average value and determining a URL to be described in the distribution URL list may be used. It is possible to create a statistically processed list without the editor's discretion. The means for editing the editable distribution URL list may be configured to automatically edit the distribution URL list based only on the data amount for new content data. The effect of caching web data with a large amount of data is great when targeting sites that can download software and data with a large amount of data. The means for editing the editable distribution URL list collects at least one of a data amount for a new content data and information on a frequency of access to each web from a client of the server computer, and based on an operator's analysis, Determine the URL to be included in the distribution URL list and It may be software for enabling the RL list to be edited. The selection of URLs to be cached shall not only be automatically selected by software, but also shall allow manual editing by the user. The information determination means at that time may be determined based on at least one of the data amount and the access frequency. The software collects both the data amount for the new content data and information on the frequency of access to each web from the client of the server computer, and writes the information in the distribution URL list based on the analysis of the operator. It may be software for determining a URL to be edited and editing the distribution URL list. The selection of URLs to be cached shall not only be made automatically by software, but shall also be possible for the user to manually edit. In addition, the information determining means at that time can determine more accurately by judging from both the data amount and the access frequency. The software collects both information on only the data amount of the new content data, determines a URL to be included in the distribution URL list based on an analysis of an operator, and edits the distribution URL list. It may be software for enabling the above. For sites that can download large amounts of software and data, it is effective to cache large amounts of data that take a long time to download. In some cases, it is preferable to rely on human prediction, and by adding flexibility to the creation of the distribution URL list, it has become possible to cope with cases where it is impossible to make predictions using only past data statistics. The software collects both information relating only to the prediction of the access frequency, determines a URL to be included in the distribution URL list based on an analysis of an operator, and edits the distribution URL list. It may be a key. By using the URL selection basis based on the access frequency, URLs of interest can be selected, and judgment can be made at the user's discretion. URLs listed in the distribution URL list are linked to well-known portal sites predetermined by the operator, and may include URLs of frequently accessed homepages based on past access information on the Internet. . Well-known portal sites are accessed frequently, and sites linked from those portal sites are necessarily accessed frequently. For this reason, including well-known portal sites includes URLs that are frequently accessed. The URL described in the distribution URL list is the URL of a file that contains at least one of software, image data, audio data, and music data whose amount of data exceeds a certain standard predetermined by the operator. You may. Software, still and moving image data, audio data, and music data generally have larger data volumes than text. Therefore, by caching a certain amount of data in advance, it is promised that communication efficiency and communication speed will be greatly improved and download time will be greatly reduced. The circulating / sending means includes, even if the URL is described in the distribution URL list, the content which is not marked as cache permitted in the HTTP header, the content which has been distributed by the communication system in the past, and the cache expiration date has expired. The content and the content in which the last update date of the content previously distributed and the last update date of the content to be distributed at the same time may include selection / control software for preventing transmission to the geostationary satellite. By removing in advance Web content data whose cache is prohibited or not required to be cached, it becomes possible to use limited memory resources effectively. The patrol / transmission means includes means for designating a URL distribution start time and enabling schedule distribution, and means for designating only the top page in the URL and collectively transmitting hyperlinked content within the same site. It may further include. Arrangement By specifying the communication start time, the data release time can be determined on the distribution side. Also, since the access frequency of the hyperlinked content may increase at once, there is an effect that the content is transmitted at once. The server computer has a plurality of clients, and the clients may include any type of server computer forming a closed network connected to the Internet via the server computer. Further, according to the present invention, a cache server which is installed in a fixed area of a geostationary satellite having a fixed area capable of data distribution, owns and manages Internet web content data, and caches cache data. The latest web content data received from individual clients of a plurality of different server computers having multicast data is distributed to other server computers via the geostationary satellite by a point-to-multipoint method. And performing a communication method based on at least one of a data amount for the content data and a prediction regarding an access frequency from a client of the server computer to the web for downloading the content data. Web content By editing at least one distribution URL list that needs to distribute the URL, new content data relating to the Web having the URL described in the distribution URL list as an address is generated, and the Regardless of whether or not there is a request for a down-link, the Web content data of the URL described in this distribution URL list is transmitted to the geostationary satellite in advance, multicast data distribution is performed, and the transmitted data is transmitted. By causing the cache to be cached in the cache server of each server computer, when a client of each server computer subsequently requests a download of content data, it is downloaded directly from the cache server of the server console to which this client belongs. Configure as possible To provide a communication method. With the provision of this method, web content data that is predicted to have a high hit rate using geostationary satellites is sent to the cache server in advance via the satellite Internet, so that terrestrial circuits are not affected. It has become possible to provide high-speed web access facilities. As described above, by providing this method, web content data and content with a large hit rate predicted to have a high hit rate using geostationary satellites can be sent to the cache server in advance via the satellite Internet. By sending it with, it became possible to provide high-speed web access privileges without affecting the terrestrial line. In other words, regardless of whether or not there is a request for a content download from the client, a web content with the URL described in the distribution URL list is transmitted to the geostationary satellite in advance, and point-to- The multicast data is distributed to each server computer by the multipoint method, and the distributed data is cached in the cache server of each server computer. After that, the content data is transmitted from the client of each server computer. When a download request is issued, it is possible to download directly from the server's cache server to which this client belongs. In the communication method according to the present invention, before receiving a download request from each client, the web content server of the URL described in the distribution URL list is transmitted to the geostationary satellite in advance, and each of the URLs is transmitted by the point-to-multipoint method. Multicast data is distributed to the server computer, and the distributed data is cached in the cache server of each server computer. Therefore, each client simply downloads the data directly from the cache server of the server computer to which the client belongs. Just do it. For this reason, as in the past, for each download request, independently manage clients that have requested downloads from a server computer that has a website for down-logging. There is no need to send data over the Internet to the server computer₍ The server computer that manages this client and the server computer that has the website for download are not always directly connected, but are often connected via one or more other server computers. However, when the communication system and the communication method of the present invention are used, the multicast data is distributed to each server computer in a point-by-point multi-point manner using a geostationary satellite. Ultra-high-speed and highly-efficient data distribution is possible regardless of the network structure of the undersea communication network and the capacity of communication lines. Furthermore, since the distributed data is cached in the cache server of each server computer, each client can simply download the data directly from the cache server of the server computer to which the client belongs. In other words, there is no need to send data via the Internet until the server computer that independently manages each client every time there is a download request from the client. The use of the communication system and the communication method of the present invention makes it possible to significantly reduce the time required for server computer overnight data communication, which significantly reduces the communication cost incurred by Internet service providers. Connect. In this way, since multicast data is distributed to each server computer by the point-to-point multipoint method using the geostationary satellites, the huge and high-speed data distribution between each server computer requires the existing ground and sea floor. Do not use communication lines. Therefore, it is possible to respond sufficiently without expanding existing ground and submarine communication lines. Hereinafter, preferred modifications of the communication method according to the present invention will be described. If at least one of the server computers did not completely receive the web content data distributed from the geostationary satellite, a reception report to that effect The data is sent to the communication system management server computer via the Internet, and based on the reception report, the communication system management server computer does not receive the data from the server computer that did not completely receive the web contents data. May be transmitted via the Internet. If at least one of the server computers does not completely receive the web content data distributed from the geostationary satellite, it sends a reception report to that effect to the communication system management server computer via the Internet. Based on the reception report, the communication system management server computer transmits the data not received to the geostationary satellite again, so that the geostationary satellite distributes the data again. It may be configured to be able to receive data completely. Since data can be resent to a server that has not completely received the data, the reliability of data transmission is further increased. Access frequency information that enables the use of software to collect and analyze information on the frequency of access to each web from a client of the server computer and determine the URL to be included in the distribution URL list. It is possible to automatically collect and analyze the URLs and edit the distribution URL list. Judging from access frequency, there is no danger of leaking popular URL. Also, human costs and mistakes for creating distribution lists can be reduced, and lists can be created quickly. The access log information of each server computer is obtained, the access log information is integrated to determine a value reflecting the access frequency of each web on the Internet, and the distribution URL list is determined based on the value reflecting the access frequency. The URL may be determined so that it is described in the table. By calculating the access frequency using the access log, a URL that actually reflects the popularity of the URL can be created, and the effect of cashing is high. Each computer on the Internet included in the access log information of each server computer Even if a value of the web access frequency is weighted in advance for each server computer, an addition value or an arithmetic mean value of the weighted values is calculated, and a URL is determined to be included in the distribution URL list. Good. It is possible to reflect the editor's intention not only by simple access frequency but also by weighting. The weight of the access frequency of each web on the Internet included in the access log information of each server computer is not weighted, and the added value or arithmetic average is calculated and the URL is determined to be described in the distribution URL list. May be. It is possible to create a statistically processed list without the editor's discretion. The editable URL list may be edited based only on the data amount for new content data. This has the effect of caching large amounts of web data when targeting downloadable sites such as large software and large data. In order to collect at least one of the information on the amount of data for new content data and the frequency of access to each web from the client on the server computer, and to enter in the distribution URL list based on the analysis of the operation The URL may be determined and the distribution URL list may be edited. The selection of URLs to be cached shall not only be automatically selected by software, but also shall allow manual editing by the user. In addition, the information determining means at that time may determine based on at least one of the data amount or the access frequency. Gather both information on the amount of new content data and the frequency of access to each web from the client of the server computer, and determine the URL to be included in the distribution URL list based on the analysis of the operation Then, the distribution URL list may be edited. The selection of the U R to be cached shall not only be automatically selected by software, but also shall be possible for the user to manually edit. In addition, the information determining means at that time can make a more accurate determination by making a determination based on both the data amount and the access frequency. Both the information on only the data amount for the new content data may be collected, the URL may be determined to be included in the distribution URL list based on the analysis of the operator, and the distribution URL list may be edited. If you are targeting downloadable sites such as software and data with a large amount of data, it is effective to cache a large amount of data with a long download time. In some cases, it is preferable to rely on human prediction, and by adding flexibility to the creation of the distribution URL list, it is possible to respond to cases where it is not possible to make predictions using only past data statistics. This is software that collects both information relating only to predictions regarding access frequency, determines the URL to be included in the distribution URL list based on the analysis of the operator, and edits the distribution URL list. You may. By using the access frequency as the basis for selecting a URL, it is possible to select a purely popular URL, and it is possible to judge it at the user's discretion. URLs listed in the distribution URL list are linked to well-known portal sites predetermined by the operator, and include URLs of frequently accessed homepages based on past access information on the Internet. Good. Well-known portal sites are accessed frequently, and sites linked from those portal sites are necessarily accessed frequently. Therefore, including a well-known portal site includes URLs that are frequently accessed. Even if the URL described in the distribution URL list is a URL of a file containing at least one of software, image data, audio data, and music data, the data amount of which is larger than a certain standard predetermined by the operator. Good. Software, image data, audio data, and music data generally have more data than text. By caching a certain amount of data in advance, it is promised that communication speed and communication efficiency will be greatly improved and download time will be greatly reduced. Content that is listed in the delivery URL list but is not marked as cacheable in the HTTP header, content that was previously delivered by this communication system, content whose cache has expired, and The content in which the last update date of the once-distributed content and the last update date of the content currently being distributed do not have to be transmitted to the geostationary satellite. By removing web content data that is prohibited or unneeded by cache in advance, it becomes possible to use limited memory resources effectively.

It is also possible to specify the distribution start time of the URL to enable schedule distribution, or to specify only the top page in the URL and transmit the hyperlinked content within the same site at once. By specifying the distribution start time, the data release time can be determined on the distribution side. In addition, since the access frequency of the hyperlinked content may increase at once, there is an effect that the content is transmitted at once. A plurality of different servers installed in a fixed area of a geostationary satellite having a fixed area that can distribute data, and having a cache server for owning and managing Internet content data on the Internet and for caching cache data In a communication method for delivering the latest content data of the web received from each client of a server computer to another server computer via the geostationary satellite by a point-to-multipoint method, a multicast data is transmitted. If at least one of the server computers has not completely received the web content data distributed from the geostationary satellite, it sends a reception report to that effect to the communication system management server computer, and the communication system management server —BaCompu Based on Ichito, to provide a communication method and transmits the data has not been received to the server computer that was not completely received content data of the web. Since data can be resent to a server that did not completely receive the data, the reliability of data transmission has increased. The reception report is transmitted to the communication system management server computer via the Internet, and data not received by the server computer which has not completely received the web content data is transmitted to the Internet. It may be transmitted via. By retransmitting on the Internet, retransmission can be performed only to the retransmission target server, and transmission and reception are possible. The reception report is transmitted to the communication system management server computer via the Internet, and the communication system management server computer transmits data not received again to the geostationary satellite based on the reception report, The geostationary satellite may perform the data distribution again to enable the server computer to completely receive the web content data. In particular, if there are a large number of servers that could not be received, it may be more efficient to collectively retransmit on a satellite rather than responding individually on the Internet. At that time, satellite retransmission is enabled. The distribution URL is based on at least one of a data amount for the content data and a prediction regarding the frequency of access from the server computer client to the web in order to download the content data. By editing the list, after a new content data regarding the web having the URL described in the distribution URL list as an address is generated, regardless of whether or not the client requests a download of the content data, Instead, the web content server of the URL described in the distribution URL list is transmitted to the geostationary satellite in advance, and the geostationary satellite transmits the multicast data to the other server computers using the point-to-point multipoint method. And send the sent data to each server computer's cache. When the client of each server computer requests a down-loading of the content data afterwards, it is downloaded directly from the cache server of the server computer to which this client belongs. May be configured to be possible. Distribute updated content immediately when content is updated Then, the latest data will always be cached. The step of obtaining the latest content of the communication system management server computer and transmitting it to the geostationary satellite includes periodically circulating the URLs described in the distribution URL list and automatically collecting the latest content data from the server computer. Patrol · Automatically collect and send the latest content data to geostationary satellites. _C By conducting a regular patrol, it will be easier to always find the latest content. The editable distribution URL list is edited by collecting and analyzing information on the frequency of access to each web from the client of the server computer and determining a URL to be included in the distribution URL list. You may. Judging from access frequency, there is no risk of leaking popular URLs. Also, human costs and mistakes for creating distribution lists can be reduced, and lists can be created quickly. The access log information of each server computer is obtained, the access log information is integrated to determine a value reflecting the access frequency of each web on the Internet, and the distribution URL list is determined based on the value reflecting the access frequency. URL may be determined to be described in the table. By calculating the access frequency using the access log, it is possible to create a URL that actually reflects the popularity of the URL, and it is highly effective in caching. The access frequency value of each web on the Internet included in the access log information of each server computer is weighted in advance for each server computer, and the sum of the weighted values or the arithmetic mean is calculated. The URL may be determined to be included in the distribution URL list. It is possible to reflect the editor's intention not only by simple access frequency but also by weighting. Calculate the added value or arithmetic mean without weighting the access frequency value of each web on the Internet included in the access log information of each server computer and determine the URL to be included in the distribution URL list May be. Editor's It is possible to create lists that perform statistical processing without discretion. The distribution URL list may be automatically edited based only on the data amount for new content data. This is effective in caching large amounts of web data when targeting downloadable sites such as software and data with large amounts of data. At least one of the information on the data amount for the new content data and the frequency of access to each web from the client of the server computer is collected, and the URL is entered in the distribution URL list based on the analysis of the operation. The distribution URL list may be determined and edited. The selection of URLs to be cached shall not only be automatically selected by software, but also shall allow manual editing by the user. In addition, the information determining means at that time may determine based on at least one of the data amount or the access frequency. Gather both information on the amount of new content data and the frequency of access to each web from the client of the server computer, and determine the URL to be included in the distribution URL list based on the analysis of the operation Then, the distribution URL list may be edited. The selection of URLs to be cached shall not only be automatically selected by software, but also shall allow manual editing by the user. In addition, the information deciding means at that time makes a more accurate judgment by judging from both the data amount and the access frequency. Both the information on only the data amount for the new content data may be collected, the URL may be determined to be included in the distribution URL list based on the analysis of the operator, and the distribution URL list may be edited. For downloadable sites such as software and data with a large amount of data, it is effective to cache large amounts of web data that takes a long time to download. In addition, judgment can be made at any discretion so that the user can edit the work manually. It is also possible to collect both information regarding only the prediction regarding the access frequency, determine the URL to be included in the distribution URL list based on the analysis of the operator, and edit the distribution URL list. By using the access frequency as the basis for selecting URLs, it is possible to select purely popular URLs, and to judge them at the user's discretion. The URLs listed in the distribution URL list are linked to well-known portal sites predetermined by the operator. May be included. Well-known portal sites are accessed frequently, and sites linked from those portal sites are necessarily accessed frequently. For this reason, including well-known portal sites includes URLs that are frequently accessed. The URL described in the distribution URL list is the URL of a file containing at least one of software, image data, audio data, and music data whose data amount is larger than a certain standard predetermined by the operator. Is also good. Software, image data, audio data, and music data generally have larger data volumes than text data. Therefore, caching a certain amount of data in advance saves downtime. Content that is listed in the delivery URL list but is not marked as cacheable in the HTTP header, content that was previously delivered by this communication system, content whose cache has expired, and It is not necessary to transmit to the geostationary satellite the content in which the last update date of the content distributed once and the last update date of the content to be distributed now match. By preliminarily removing web content data for which cache is prohibited or unnecessary, limited memory resources can be used effectively.

Specify the distribution start time of the URL and perform schedule distribution, specify only the top page in the URL, and collectively link hyperlinked content within the same site May be sent. By specifying the distribution start time, the data release time can be determined on the distribution side. Also, since the access frequency of the hyperlinked contents may increase at once, there is an effect that the contents are transmitted at once.

Embodiment An embodiment of the present invention will be described with reference to the drawings with respect to an example of a system and an example of a method. FIG. 1 shows an overall configuration diagram of a communication system according to the present invention. The communication system is composed of a transmitting system 33, a receiving system 34, a geostationary satellite 4, and the Internet 12. The transmitting system 3 3 and the geostationary satellite 4, and the receiving system 3 4 and the geostationary satellite 4 are electrically connected by a wireless satellite link. That is, the transmitting system 33 and the receiving system 34 are electrically connected via the geostationary satellite 4. On the other hand, the transmission system 33 and the reception system 34 are electrically connected via a wired internet 12. This system is a system in which a transmitting system 33 and a receiving system 34 are complementarily connected via a geostationary satellite 4 and an internet 12. The transmission system 33 is a system for transmitting Internet information to the geostationary satellite 4. Transmission system 3 3 \ same? ? It consists of a server 1, a satellite multicast transmitter 2, a parabolic antenna 3, a switch 9, a web analytics' collection server 7, and a router 10. WCPP server 1 is electrically connected to satellite multicast transmitter 2, and satellite multicast transmitter 2 is electrically connected to parabolic antenna 3. The parabolic antenna 3 is electrically connected to the geostationary satellite 4 by wireless communication with the geostationary satellite. On the other hand, the WCPP server 1, the web analysis and collection server 7, and the router 10 are electrically connected to each other via the switch 9. Further, the router 10 is electrically connected to the Internet 12. The WCPP server 1 is loaded with the transmission system program of the present system and controls the transmission system. In addition, the web server collects the web data collected by the web analysis / collection server 7 from In-Yuichi Net 12 and transmits it to the satellite multicast transmitter. The satellite multicast transmitter 2 converts the format of the web information bucket for the receiving system transmitted from the WCPP server 1 from the IP multicast format to the satellite multicast format, modulates it to electromagnetic waves, and transmits it via the parabolic antenna 3 To geostationary satellite 4. The parabolic antenna 3 radiates electromagnetic waves transmitted from the satellite multicast transmitter 2 toward the geostationary satellite 4. The web analysis / collection server 7 collects web data predicted to have a high hit rate from web sites 13-1, 13-2, and 13-n connected to the internet 12. For this purpose, edit the URL list of the websites with high hit rates, 13-1, 13-2, and 13-n. In addition, web patrol robots 56 are used for web collection. Further, the collected web data is transmitted to the WCPP transmitter server 1 via the switch 9. The switch 9 connects a server on the LAN in the transmission system 33. Specifically, the WCPP transmitter server 1, the web analysis and collection server 7, and the router 10 are connected. The device 10 is an input / output device for the transmission system 33 LAN to the Internet 12. Specifically, it is connected to the switch 9 and the internet 12. The geostationary satellite 4 receives the satellite multicast type electromagnetic wave on which the web data with a high hit rate transmitted from the transmission system 3 3 is superimposed, and receives one or a plurality of reception waves in an area where the geostationary satellite 4 can transmit. It retransmits to the system 34 a satellite multicast electromagnetic wave on which web data with a high hit rate is superimposed. For this reason, web data with a high hit rate exists in the area where geostationary satellite 4 can transmit A large amount of data can be transmitted to a receiving system at the same time and at high speed without imposing a load on the Internet line. The receiving system 34 includes a WCPP client 6, a satellite multicast receiver 5, a parabolic antenna 3, a proxy server 8, a client server 11, a switch 9, and a router 10. The WCPP client 6 is electrically connected to the satellite multicast receiver 5, and the satellite multicast receiver 2 is electrically connected to the parabolic antenna 3. The parabolic antenna 3 is electrically connected to the geostationary satellite 4 by wireless communication with the geostationary satellite. On the other hand, the WCPP client 6, the proxy server 8, and the router 10 are electrically connected to each other via the switch 9. Further, the router 10 is electrically connected to the Internet network 12.

The WCPP client 6 is loaded with the program of the receiving system of the present system, and controls the receiving system. In addition, it receives web data predicted to have a high hit rate transmitted from the satellite multicast transmitter 5 and pushes it to the proxy server 8 via the switch 9. The satellite multicast receiver 5 demodulates the format of the web data bucket received from the geostationary satellite 4 via the parabolic antenna 3 and predicted to have a high hit rate from electromagnetic waves and converts it from satellite multicast format to IP multicast format. And sends it to WCPP server 1. The parabolic antenna 3 receives the electromagnetic wave transmitted from the geostationary satellite 4 and transmits it to the satellite multicast transmitter 2. Its size is preferably 120 cm in diameter. The proxy server 8 caches the web data transmitted from the WCPP client 6 which is predicted to have a high hit rate. Client server 1 1 is connected to switch 9 and stored in proxy server 8 Utilize web data. The switch 9 connects a server on the LAN in the receiving system 34. More specifically, WCPP receiver server 6, proxy server 8 and 10 are connected. The router 10 is an input / output device for the transmission system 34 LAN to the Internet 12. Specifically, it is connected to the switch 9 and the Internet 1-12. The Internet 12 is connected to both the transmission system 33 and the reception system 34, and is used for transmitting and receiving data that does not impose a load on a small amount of network compared to a satellite line. Necessary websites are connected to the Internet 12. There are a large number of websites 13 at present, and the websites that are predicted to have a high hit rate are listed in Figure 1. The protocol layer of the communication system according to the present invention will be described with reference to FIG. 2 according to the OSI basic reference model. The OSI basic reference model consists of seven layers. The order of operation is application layer 35, presentation layer 36, transport layer 37, session layer 38, network layer 39, data link layer 40, and physical layer 41. The application layer 35 is a layer that provides services that can be used by actual applications. The presentation layer 36 is a layer for converting a data representation format (character set, data compression, encryption, etc.). The session layer 37 is a layer that controls orderly data transmission / reception so that communication can be realized as conversation. The transport layer 38 realizes data order control, transfer error recovery, etc. It is a layer that guarantees the quality of the communication. The network layer 39 is a layer for selecting and relaying data transfer routes. The data link layer 40 is a layer that collects signals (bit strings) received from the physical layer as meaningful data and provides data transmission control procedures such as transmission error control. The physical layer 41 is a layer that defines media such as cables and connectors used for communication, electrical signal standards, and the like, and realizes transfer of signals between devices.

In the OSI basic reference model, communication is performed after combining the above seven layers of communication functions. Next, regarding the communication system according to the present invention, the protocol of each layer will be described specifically for the transmission system 33 and the reception system 34. Transmission system 33 consists of WC PP server software 21, satellite IP multicast transmission library 23, UDP 25, TCP 26, IP 27, PDMC 28, Ether 29, satellite communication transmitter 2 and Internet Consists of 1 and 2.

The WCPP server software 21 corresponds to the application layer of the transmission system 33, and is a program for collecting web data predicted to have a high hit rate from the Internet beforehand. The satellite IP multicast transmission library 23 corresponds to the presentation layer 36 and the session layer 37 of the transmission side system 33. The satellite IP multicast transmission library 23 is a program that transmits, as a bucket, the web data collected by the WCPP server software 21 and predicted to have a high hit rate.

UDP 25 corresponds to the transport layer 38 for satellite communication of the transmitting system 33. UDP 25 provides a connectionless datagram communication service with an interface to the satellite IP multicast transmission library 23 I do.

The TCP 26 corresponds to the transport layer 38 for the Internet 12 of the transmitting system 33. TCP 26 provides connection-based, reliable stream communication services.

IP 27 corresponds to the network layer 39 of the transmission side system 33. IP 27 is a protocol that implements communication between hosts or between hoses and gateways.

The PDMC 28 corresponds to the satellite-side data link layer of the transmission system 33. The PDMC 28 transmits the IP multicast packet to the satellite multicast packet.

The Ethrenet 29 corresponds to a data link layer on the internet side of the transmission system 33. Ethernet 29 is composed of logical link control and media access control, handles data in a frame structure, and controls transmission errors. The satellite communication transmitter 2 corresponds to the physical layer 41 for the satellite of the transmission system 33. The satellite communication transmitter 2 transmits the satellite multicast bucket to the geostationary satellite 4 as an electromagnetic wave. The internet 12 corresponds to the physical layer 41 of the transmission system 33 for the internet. The Internet 12 specifically means a cable or the like, and means transmission and reception in bit units. The receiving system 34 consists of WC PP server software 22, satellite IP multicast reception library 24, UDP 25 TCP 26, IP 27, Direc PC 30, Ether 29, satellite communication receiver 5 and Internet 12 It is composed.

WC PP server software 22 is an application of the receiving system 33 Corresponds to a layer. The WC PP server software 22 is a program for caching web data that is predicted to have a high hit rate to the proxy server. This corresponds to session layer 37. The satellite IP multicast reception library 24 is a program that receives, as a bucket, web data transmitted from the geostationary satellite 4 and predicted to have a high hit rate. ,

UDP 25 corresponds to the transport layer 38 for satellite communication of the receiving system 34. UDP 25 provides a connectionless datagram communication service having an interface with the satellite IP multicast reception library 23.

The TCP 26 corresponds to the transport layer 38 for the Internet 12 of the receiving system 34. TCP 26 provides connection-based, reliable stream communication services.

IP 27 corresponds to the network layer 39 of the receiving system 34. IP27 is a protocol for realizing communication between hosts or between a host and a gateway.

The Direc PC 30 corresponds to the satellite-side data link layer of the receiving system 34. DirecPC 30 converts satellite multicast buckets to IP multicast buckets.

The Ethernet 29 corresponds to an overnight link layer of the receiving system 34 on the Internet side. Ethernet 29 includes logical link control and media access control, handles data in a frame structure, and controls transmission errors. The satellite communication receiver 5 corresponds to the physical layer 41 for the satellite of the receiving system 34. The satellite communication receiver 5 receives the satellite multicast bucket from the geostationary satellite 4 as an electromagnetic wave. The Internet 12 corresponds to the physical layer 41 of the receiving system 34 for the Internet. In-Yuichi Net 12 specifically means a cable or the like, and means transmission and reception in bit units. By having the above protocol, it is possible to smoothly exchange data between the Inuichi Net 12 and the satellite multicast. FIG. 3 shows an overall procedure diagram of the communication system according to the present invention. This communication system consists of four major steps. The first procedure is distribution URL list editing processing 53. The distribution URL list editing processing 53 edits the URL list of the web that the web patrol robot 56 patrolls. The input contents are an editing operation 51 and a popular URL list 52. The output content is a distribution URL list 54. The purpose of this process is to distribute the popular URL list specified by the operator and add it to the URL list. By executing this editing process, it is possible to set in advance the URL of the web predicted to have a high hit rate. For this reason, in addition to setting URLs of already popular webs, it is possible to set URLs of webs that are expected to increase in the future in the future. It is possible to place a cache. The second step is a web patrol robot 56. The purpose of this procedure is to automatically collect the web data of the URL specified in the delivery URL list in the order of the delivery URL list. The input contents of the web patrol port 56 are a distribution URL list 54 and a web server 55. The output contents of the web patrol robot 56 are ゥ data. See also Web data cache expiration date 57. The web patrol robot 56 enables automatic collection of web data with a high hit rate in advance, so that data can be collected during a time when access to the web with a high hit rate is not concentrated. The third procedure is satellite IP multicast59. Satellite IP Multicast The purpose of G59 is to broadcast the web data automatically collected by the web patrol robot. The input contents of the satellite IP multicast 59 are automatically collected web data. The output of satellite IP multicast 59 is web data to the proxy server of each receiving system. By performing this procedure, data can be sent to all receiving servers in any location within the receivable area of the geostationary satellite 4, so that data can be sent to many servers. Furthermore, since it is satellite communication, a large amount of data can be transmitted at the same time. In the Internet, the communication speed of the network near the server is reduced because many cables are branched, and when a large number of buckets are transmitted at one time, the transmission speeds are reduced, but such problems do not occur. . The fourth step is Web Push 60. The purpose of the WCPP client 60 is to receive web data sent by satellite multicast and push it to the proxy server's cache. The input content of the WCPP client 60 is web data. The output content of the WCPP client 60 is also web data to the proxy server 62. By performing this procedure, the data received from the geostationary satellite 4 can be cached in the proxy server 62. That is, when connecting to the Internet 12 from the client server 11 via the proxy server 62 and accessing the web with a high hit rate, the web data existing in the cache on the proxy server 62 is obtained. As a result, it is possible to obtain Web data at a speed faster than obtaining Web data from an actual Web server and without any difference from Internet access. The overall procedure of the communication system according to the present invention has been described above. Each procedure is described in more detail. In the distribution URL list editing process, in detail, add popular URL list, delete URL, delete distributed URLs in batch, modify URL, specify distribution start time for URL, specify automatic traversal of hyperlink carry out. Adding a popular URL list means automatically or manually adding a popular URL to the distribution URL list. With this function, web URLs with high hit rates can be added to the distribution list in real time.

Deleting URLs means deleting URLs that have already been delivered and URLs that have become unnecessary due to a reduced hit rate, and reduce unnecessary network traffic and effective use of memory resources. Deletion of delivered URLs means simultaneous delivery of multiple URLs simultaneously, so multiple delivered URLs occur simultaneously. For this reason, it is possible to automatically delete all the delivered URLs.

URL modification means that server changes are frequently made on the Internet. Therefore, especially on the Web that is distributed for a long period of time, the URL may be changed sufficiently after registering the distribution list. Also, when inputting the URL manually, the possibility of erroneous input is not 0, so correction is necessary.

Specifying the delivery start time for a URL means that it is updated periodically depending on the URL, so it is desirable to obtain data by patrol after updating. It is also used when it is desirable to distribute and circulate when traffic is too low due to network traffic. Automatic traversal designation of hyperlinks means that link information is also described in web data, so it is necessary to perform automatic traversal also at the link destination, and to specify the hierarchy when performing. The above has described the details of the distribution URL list editing process. Next, the Web tour robot will be described with reference to FIGS. Figure 4 describes the details of the procedure for implementing a web patrol robot. The web patrol robot can simultaneously execute multiple child processes 56-1, 56-2, ~ 5 6—n is executed. A plurality of child processes 56-1, 56-2, to 56-n obtain Web data from different web servers 55-1, 55-2, to 55-n described in their own distribution URL lists. Each of the plurality of child processes 56-1, 56-2, to 56-n hands over the respective web data to a different buffer process 64_1, 64-2, to 64-n. Each of the different buffer processes 64-1, 64-2,..., 64-n passes all web data to the satellite transmission process 65. The buffer management library 66 provides a synchronization mechanism between the buffering side and the data fetching side when the buffering operation and data fetching from the buffer are performed asynchronously and simultaneously. In the satellite transmission process 65, each web data is transmitted to the satellite IP multicast 59 in the order of acquisition. The satellite transmission process 65 acquires the buffered web data in order using the buffer management library, and sends the web data to the UDP port of the multicast IP address written at the top of the buffer. Perform satellite multicast transmission using the I library. The satellite transmission process 65 adjusts the transmission speed so that data transmission does not exceed the bandwidth specified by the parameter. As described above, the web patrol robot 56 simultaneously obtains a plurality of URLs in order to obtain web data at high speed. However, since satellite IP multicast API-59 transmits serialized data to the same port number of the same multicast address and transmits data, satellite IP multicast transmission is performed by serializing data in order from the acquired web data. Perform transmission. By performing multiple web tour robots simultaneously and in parallel, it is possible to obtain a large amount of web data at a higher speed than in the case of serial execution. On the other hand, satellite lines have a sufficiently wide transmission range per line, so even if serial transmission is used, Since web data can be sent to all necessary servers, send web data in the serial. Also, by transmitting serially, it is possible to effectively use a high-cost satellite circuit. In order to suppress unnecessary data transmission, the "cache control" and "object update date" information described in the HTTP header are used as data management information items. Web patrol robots consist of two types of processes and one type of shared library. The web patrol robot process 56, the satellite communication process 65, and the buffer 64. The web patrol robot generates multiple child processes and processes a single delivery URL list asynchronously and simultaneously. In the evening, buffered web data is transmitted by satellite IP multicast in the order of buffering completion by the satellite transmission process that is always running as a daemon. Figure 5 is a further child of the web crawl process. The first child process is the cache expiration date cleanup process. The expiration date is set in advance for the cache contents to become obsolete every day, and after the expiration date, the cache contents are updated. The cache expiration date cleanup process deletes cache data whose expiration date has passed from the cache expiration date file 57 to prevent the cache from increasing. The second child process is the access prohibited URL list cleanup process. Prohibit redistribution of delivered URLs to improve delivery efficiency. The list of the prohibited contents is the access prohibited URL list 67. That is, the distribution URL list is described in the access prohibition URL list 67 after distribution. For this reason, it will only increase by distribution. The access prohibition URL list cleanup process deletes a record whose acquisition time has passed the reacquisition time or more from the access prohibition URL list 67. While the above two processes are being performed, the web patrol port 56 obtains a URL from the distribution URL list 54 and accesses the web server 55 according to the URL to collect web data. The web patrol port pot 56 sends the collected web data to the buffer 64. Figure 6 illustrates satellite IP multicast 59. Satellite IP multicast 59 is roughly divided into a transmitting system 33 and a receiving system. First, the procedure of the transmitting system is described step by step. First, the transmission application process 99 transfers the web data to the satellite IP multicast transmission library 23 with the transmission variable length record 103. Second, the satellite IP multicast transmission library 23 converts the variable-length record into a fixed-length bucket to the receiving system 34, and transmits the packet separately. Third, the satellite IP multicast transmission library 23 transmits management information describing the number of divided packets to the reception system 34 prior to record transmission. Fourth, the satellite IP multicast transmission library 23 assigns a record sequence number and a bucket sequence number to the bucket as transmission packet arrival sequence management information. Fifth, the satellite IP multicast transmission library 23 adds a checksum to the packet in order to monitor data corruption. Sixth, the satellite IP multicast transmission library 23 writes a copy 105 of the transmission bucket into the retransmission control buffer 94 for error recovery. The retransmission control buffer 94 stores the satellite communication delay time (250 ms) + the Internet delay time from the receiving terminal to the transmission center (200 ms) + α time packets. To be able to Seventh, when the library is initialized, a retransmission request acceptance process 95 is created as a child process. Eighth, if there is a retransmission request 106 from the receiving system 34 in the retransmission request receiving process 95, a packet retransmission process 96 is generated as a child process, and the requested packet is retransmitted. By following the above procedure, bucketing of web data was implemented and satellite IP multicast transmission became possible. Furthermore, since there is a packet retransmission process in response to a retransmission request, a procedure has been built in advance to enable retransmission and correct reception even if web data could not be received correctly by the receiving server. I have. Next, the procedure of the receiving system 34 will be described step by step. The satellite IP multicast receiving library has a role to receive the packet transmitted to the multicast IP address specified at the time of library initialization, assemble it into a record, and pass it to the application. First, assemble the fixed-length receiving bucket into a variable-length record and deliver it to the application. Second, recalculate the checksum of the received data and monitor the data garbled over the received data. Third, based on the record sequence number and bucket sequence number of the received data and the number of bucket divisions, it manages the arrival sequence of the received buckets and monitors the bucket lost. Fourth, when the received data is garbled or a packet loss is found in the second and third procedures, a bucket retransmission request 106 is made to the “retransmission request receiving process 95” on the transmission system side. Fifth, when the satellite IP multicast reception library 24 is initialized, a “preceding reception process” is created as a child process, and the data received asynchronously with the main processing is stored in the reception buffer 97. The above is the procedure of the receiving system 34. By following this procedure, it is possible to receive web data in a form assembled into a record. In addition, monitoring of data errors in received data packets and monitoring of bucket storms have become possible, and measures have been put in place to improve the reliability of data reception. Also, by using the advance reception process 98, it is possible to record a buffer of all received data. Figure 7 shows the web push procedure. The web push program exists in the WCP P client 6 (shown in FIG. 1), and aims to receive web data sent by satellite IP multicast and push it to the proxy server 8. First, the sipling 82 intentionally requests a dummy HTTP request to the proxy server 81 for the URL of the data received from the satellite 68 (dummy HTTP request 69). This URL exists in sip ring 82 and does not exist in the proxy server. Second, the proxy server 81 conducts an inquiry by ICP as to whether data exists in the sip ring 82 (ICP inquiry 71). Thirdly, in cycling 82, the URL of ICP inquiry 71 always exists because it has already been received from the satellite 72. Answer to the proxy server that there is data as an ICP response (ICP response: yes 73). Fourth, since the proxy server 81 was able to confirm the existence by the ICP inquiry, it makes an HTTP request to the sibling 82 74 (HTTP request 75). Fifth, since the HTTP request 75 was issued from the proxy server 81, the corresponding web site is transmitted to the proxy server 81 (HTTP acquisition 77). Sixth, the proxy server 81 stores the web data received from the geostationary satellite 4 in a cache. The cached data is transmitted in response to the dummy HTTP request 78 (Dummy HTTP acquisition notification 79). Seventh, sipling 82 discards HTTP acquired data 80. As described above, the web data moves to the proxy server 81 from the sip ring 82, and when a request is made to the proxy server 81 for the HTP of the web server with a high hit rate, the data is obtained and a series of objectives is achieved. Is done. Figure 8 shows the process configuration of the WCP P client 90. The WC PP client 90 includes a satellite reception process 82, a cache 83, a reception 1; a list 84, an HTTP client 81, an ICP server 85, an HTTP server 86, a cache cleanup 87, and a log cleanup 88. You. The satellite reception process 82 obtains the received data from the satellite IP multicast 59. The URL received by the satellite reception process 82 is described in a reception URL list 84. When the log cleanup 88 is invoked, it reduces all incoming URL lists that have passed the time specified by the argument. The satellite reception process 82 is connected by a pipe to HTTP.

The HTTP client 81 exchanges HTTP with the proxy server 89. The satellite reception process 82 records the consultation result in the cache 83. The data in the cache is sent to the CCP server 85.

The ICP server 85 exchanges ICP with the proxy server 89. The cache 83 also exchanges data with the HTTP server 86.

The HTTP server 86 has the same HTTP server function as the ordinary proxy server 89. However, the following two points are different. The first did not hit the cache In that case, it is to return NO t Found without going to the original web server to retrieve the web data. The second is to clear the cache after transmitting the web data stored in the cache. The HTTP server supports multi-session. When a connect request is made via HTTP, a child process is created using the fork 0 system call, and each process responds to the request from the HTTP client. When Cache Cleanup 87 is activated, it deletes cached data that has passed the time specified by the argument. Next, details of each process will be described. The satellite reception process 82 will be described with reference to FIG. The satellite reception process 82 receives the web data transmitted by the satellite IP multicast and adds it to the cache 83. When the addition to the cache 83 is completed, the received URL is added to the pipe connected to the standard input of the HTTP client 81 and the received URL list. The satellite reception process 82 starts when the satellite reception process 82 starts, with the HTTP client 81 as a child process, and continues to start until the satellite reception process 82 ends. The HTTP client 81 redirects the standard input to the satellite reception process and receives an instruction from the standard input.

The HTTP client 81 makes an HTTP request to the proxy server 89 specified by the argument with the URL specified by the standard input, and discards the web data received from the proxy server. From the above, the HTTP client performs the dummy HTTP request in the web push procedure. In FIG. 10, the ICP server 85 will be described. The ICP server 85 establishes a sip relationship with the proxy server 89 specified by the argument, and responds to the request from the proxy server 89. When the ICP server (request reception 91) starts, it generates a child process for response transmission with the fork 0 system call, and redirects the pipe to the standard input for response transmission. Request acceptance 91 writes an ICP request to a pipe and uses the pipe as a FIFO. In response transmission, the ICP request is read from the standard input, the cache 83 is searched, and the search result is sent to the proxy server as an ICP response. From the above, it is possible to confirm the presence or absence of the requested web data in the cache 83 in which the data received by the satellite by the ICP server is stored. FIG. 11 illustrates measures for improving the reliability of the communication system. The weak point of this communication system is that if the sending side stops due to some kind of failure, all data delivery stops. Therefore, a duplex configuration is adopted in which the backup system operates even if one of the transmitting systems stops, and the distribution does not stop. First, the slave server on the sending side is connected to the master server on the sending side 115. The transmitting slave server 1 16 starts a monitoring process 1 12 that monitors the process status table 110 of the transmitting master server 1 15. Second, when the web patrol port pot 56 is stopped or communication becomes impossible in the sending master server 115, the common error handler 108 is activated. Third, when the common error handler 108 starts and the extended process status table 110 changes, the monitoring process 112 starts and the replay web patrol robot 113 starts. Continue the patrol. The NFS server 1 1 1 is used to store web distribution lists, cache effective origins. As described above, as in Fig. 6, the server is duplexed as a countermeasure in the event of a trouble, which has a great effect for the non-stop of the transmission system. Based on the above, this communication system sends high-speed web data, which is predicted to have a high hit rate, to the cache server in advance via satellite Internet, so that high-speed transmission is possible without affecting the terrestrial line. It is possible to provide secure and secure web access.

INDUSTRIAL APPLICABILITY According to the present invention, the web content data of the URL described in the distribution URL list in advance is transmitted to the geostationary satellite regardless of whether or not the client has requested the download of the content data overnight. Multicast data is distributed to each server computer by the point-to-multipoint method, and the distributed data is cached in the cache server of each server computer. When a client requests a download of content data overnight, it is possible to download directly from the cache server of the server computer to which this client belongs. For example, a large number of download requests are sent to a popular website from a huge number of client computers managed by server computers all over the world via the Internet. However, in the communication system according to the present invention, before receiving a download request from each client, the web content data of the URL described in the distribution URL list is transmitted to the geostationary satellite in advance, and the point-to-multipoint method is used. Multicast data is distributed to each server computer, and this distributed data is transmitted to each server computer. —Since it is cached in the evening cache server, each client can simply download directly from the cache server of the server computer to which this client belongs. For this reason, as in the past, for each download request, independently from the server computer where the website for down-loading is located to the server computer where the client requesting the download is managed, There is no need to send data over the Internet. The server computer that manages this client and the server computer that has the website for down-linking are not always directly connected, and often have one or more other server computers. Therefore, when the communication system and the communication method of the present invention are used, multicast data is distributed to each server computer by a point-to-multipoint method using a geostationary satellite. Ultra-high-speed and high-efficiency data distribution will be possible regardless of the network structure of the ground- and sea-bottom communication networks connecting them and the capacity of communication lines. Furthermore, since the distributed data is cached in the cache server of each server computer, each client may simply download the data directly from the cache server of the server computer to which the client belongs. In other words, there is no need to transmit data via the Internet network to the server computer that independently manages each client every time a client requests download. For example, even if there is a request to download the same content, the current system is extremely inefficient because the same content is sent overnight for each request. However, according to the communication method and communication system of the present invention, the web content data of the URL described in the distribution URL list is transmitted to the geostationary satellite in advance before receiving a request for a down-link from each client. Because the multicast data is distributed to each server computer using the multipoint method, no matter how much the number of download requests increases, the It has no effect on the speed and efficiency of data delivery. Then, the distributed data is cached in the cache server of each server computer, and each client simply downloads the data directly from the cache server of the server computer to which the client belongs. The increased amount only increases the amount of communication between the client computer and the server computer to which this client belongs, so the capacity of communication equipment such as communication lines directly connecting the server computer with the target website And fears of exceeding their abilities. The communication system and the communication method of the present invention are more applicable when the data to be downloaded includes not only text data such as characters, but also data such as still images, moving images, audio data, music data, or various software. The benefits of improving the communication speed and communication efficiency through use become remarkable, and the effect of reducing the communication time and communication cost becomes extremely large. Most Internet service providers are responsible for the cost of communicating with server computers connected via the Internet, and clients are required to provide their own Internet service. Considering the current situation in which the costs required for communication between the provider and each client are taken into account, the use of the communication system and communication method of the present invention significantly increases the time required for data communication between server computers. Such a reduction will lead to a significant reduction in communication costs incurred by Internet service providers. As described above, since multicast data is distributed to each server computer by the point-to-multipoint method using the geostationary satellite, the huge and high-speed data distribution between each server computer requires the existing ground and sea floor. Do not use communication lines. Therefore, it is possible to respond sufficiently without expanding existing ground and submarine communication lines. In other words, there is no need to convert all current terrestrial and submarine communication lines to high-speed lines such as optical fibers, and there is no need for enormous costs. In the near future, it is expected that Internet service providers will install server computers in almost all regions of the globe, but using geostationary satellites, point-to- In order to perform multicast data overnight distribution, there is no need to extend a communication network all over the inland continent, and to realize such a full-scale Internet society on a global scale, the communication system of the present invention and It can be understood that the communication method is extremely suitable. That is, the communication system and the communication method of the present invention are novel communication systems and communication methods that can solve all of the above problems, and enable ultra-high-speed and high-efficiency Internet-based content data transmission. In particular, even if a large number of simultaneous requests for down-consumption of web content with a large amount of data are transmitted simultaneously, it is possible to transmit data in a very short time, at an ultra-high speed and with high efficiency, and to realize the current land line. Provide communication facilities that can fully respond to the Internet society of the next century without expanding the submarine line at all.

Claims

The scope of the claims

1. Ownership and management of (1) a geosynchronous satellite having a fixed area to which data can be distributed, and (2) an Internet content web site installed in the fixed area of the geosynchronous satellite, and a plurality of different server computers having Kiyasshi Yusaba to cache the key Yasshu data, means for transmitting ₍₃₎ the latest configuration Tenddeta of the web received from the at least Tsugasono client server configuration Pew evening to a geostationary satellite, (4) means for receiving the latest web content data of another server computer distributed from the geostationary satellite;

(5) means for storing an editable distribution URL list in which at least one URL required to distribute web content data is listed, wherein the geostationary satellite includes a server transmitted by the transmission means. In a communication system that distributes new content data related to the computer web to other server computers in a multicast 'two-point' multi-point system, the communication system has a data volume for the content data. And the distribution URL list can be edited based on at least one of a prediction of the frequency of access from the server computer to the web to download this content overnight. Means for making the URLs described in the distribution URL list After a new content download on the Web with the URL given as an address occurs, regardless of whether or not there is a request for download of the content download from the client, the content is listed in this distribution URL list in advance. The web content data of the URL is transmitted to the geostationary satellite, and the geostationary satellite distributes the multicast data to another server computer by a point-to-point multipoint method, and transmits the transmitted data to the cache server of each server computer. When the client of each server computer subsequently requests a down-loading of the content data, the cache of the server computer to which this client belongs is transmitted. A communication system characterized in that it can be directly down-loaded from a network server.

2. At least a plurality of the server computers have means for receiving the latest content data on the web of another server computer distributed from a geostationary satellite and storing the received latest content data in a cache server, and at least 2. The communication system according to claim 1, wherein one of said server computers has means for transmitting the latest web content data received from a client to a geostationary satellite.

3. The communication system according to claim 2, wherein at least a plurality of said server computers have means for transmitting to a geostationary satellite.

4. At least a plurality of the server computers have means for receiving the latest content data of the web of another server computer distributed from a geostationary satellite and storing the received latest content data in a cache server, and the server At least one communication system management server computer connected to the computer via the Internet is further provided, and the communication system management server computer manages the distribution URL list, and relates to the URL described in the distribution URL list. 2. The communication system according to claim 1, further comprising means for acquiring the latest content data of the web from the server computer and transmitting the latest content data to a geostationary satellite.

5. The means for acquiring the latest contents data stored in the communication system management server computer and transmitting the latest contents data to the geostationary satellite, periodically traverses the URL described in the distribution URL list, and transmits the latest contents data from the server computer. 5. The communication system according to claim 4, comprising: a traveling / automatic collecting means for automatically collecting; and means for transmitting the latest content data to a geostationary satellite.

6. The patrol / automatic collection means consists of web patrol application software built on the application layer, while the latest content data is stored statically. 6. The communication system according to claim 5, wherein the means for transmitting to the geostationary satellite comprises a multicast transmission library constructed in a presentation layer.

7. The communication system according to claim 6, wherein the web patrol application software starts as a daemon and continues executing until a system shutdown.

8. Each server computer has web push software built on the application layer for caching in the cache server, and a multicast reception library built on the presentation layer as a means to receive the latest content data on the web. The communication system according to claim 5, wherein:

9. The communication system according to claim 8, wherein the web push software starts as a daemon and continues to run until a system shutdown.

10 The communication system management server computer has a duplex configuration including a master system and a slave system, and a monitoring means provided in the slave system monitors a process status table provided in the master system by a timer. The monitoring means shuts down the main system and activates the traveling / automatic collection means in the sub system when a failure is detected in the system or when the sub system cannot communicate with the main system. The communication system according to claim 5, wherein

11 1. By further providing a common server computer that is connected to the master system and the slave system and that owns and manages the distribution URL list, shuts down the master system and starts patrol and automatic collection means in the slave system. 10. The communication system according to claim 10, wherein patrols can be performed based on the distribution URL list.

1 2. At least one of the server computers sends a reception report indicating that web content data delivered from the geostationary satellite was not completely received. The communication system management server computer further includes means for sending to the communication system management server computer via the Internet. 5. The communication system according to claim 4, further comprising means for transmitting said data via the Internet.

13. At least one of the server computers sends a reception report indicating that web content data transmitted from the geostationary satellite was not completely received to the communication system management server computer via the Internet. Means for sending to the geostationary satellite, based on the reception report, the communication system management server computer further comprising means for transmitting the data not received to the geostationary satellite again. 5. The communication system according to claim 4, wherein the distribution enables the server computer to completely receive the content data of the web.

14. The means for editing the editable distribution URL list collects and analyzes information on the frequency of access to each web from the client on the server computer, and analyzes the URL to enter the URL in the distribution URL list. 2. The communication system according to claim 1, comprising software for automatically collecting and analyzing access frequency information enabling the determination.

15 5. The software that automatically collects and analyzes the access frequency information obtains the access log information of each server computer, and integrates this access log information to determine the access frequency of each web on the Internet. 15. The communication system according to claim 14, wherein the communication system is software that determines a value to be reflected, and determines a URL to be described in the distribution URL list based on the value reflecting the access frequency.

16. The software that automatically collects and analyzes the access frequency information is provided on each Internet network included in the access log information of each server computer. The access frequency value of Eb is weighted in advance for each server computer, and an addition value or an arithmetic mean value of the weighted values is calculated, and a URL is determined to be included in the distribution URL list. 16. The communication system according to claim 15, wherein the communication system is software.

1 7. The software that automatically collects and analyzes the access frequency information does not weight the value of the access frequency of each web on the Internet included in the access log information of each server computer. 16. The communication system according to claim 15, wherein the software is software that calculates an addition value or an arithmetic average value and determines a URL to be described in the distribution URL list.

18. The means for editing the editable distribution URL list is software for automatically editing the distribution URL list based only on the amount of data for new content data. A communication system as described.

1 9. The means for editing the editable distribution URL list collects at least one of information on a data amount for a new content and a frequency of access to each web from a client of the server computer, 2. The communication according to claim 1, comprising software for determining a URL to be included in the distribution URL list based on an analysis of an operation and enabling the distribution URL list to be edited. system.

20. The software collects both the data amount for the new content data and the frequency of access to each web from the server computer client, and based on the analysis of the operator, the distribution URL 20. The communication system according to claim 19, wherein the communication system is software for determining a URL to be described in a list and editing the distribution URL list.

2 1. The software collects both information about only the amount of data for the new content data, and based on the operator's analysis, 20. The communication system according to claim 19, wherein the communication system is software for determining a URL to be described in a list and editing the distribution URL list.

22. The software collects both information relating only to the prediction of the access frequency, determines the URL to be included in the distribution URL list based on the analysis of the operator, and enables the distribution URL list to be edited. The communication system according to claim 19, wherein the communication system is software.

23. URLs listed in the distribution URL list are linked to well-known portal sites predetermined by the operator, and include URLs of websites that are frequently accessed based on past access information on the Internet. 2. The communication system according to claim 1, wherein:

24. The URL listed in the distribution URL list is the URL of a file containing at least one of software, image data, audio data, and music data whose data volume exceeds a certain standard predetermined by the operator. 2. The communication system according to claim 1, wherein:

25. The patrol / sending means includes contents that are not marked as cacheable in the HTTP header even if they are URs listed in the distribution URL list, contents that were previously distributed by this communication system, Content that has expired and that has the last update date of the previously delivered content and the last update date of the content that is currently being delivered should include selection and control software to prevent transmission to the geostationary satellite. The communication system according to claim 1, characterized in that:

26. The patrol / transmission means specifies the URL distribution start time and enables scheduled distribution, and specifies only the top page in the URL and transmits the hyperlinked content in the same site collectively 2. The communication system according to claim 1, further comprising: means.

27. The server computer having a plurality of clients, the clients including any type of server computer forming a closed network connected to the Internet via the server computer. Item 2. The communication system according to Item 1.

28. Ownership and management of (1) a geosynchronous satellite having a fixed area to which data can be distributed, and (2) an Internet web content server installed in the fixed area of the geosynchronous satellite. A plurality of different server computers each having a cache server for performing a cache server, and (3) at least one communication system management server computer connected to the server computer via the Internet, In addition, the communication system management server computer stores an editable distribution URL list in which at least one URL required to distribute the web content data is listed. A communication system management server computer having means for managing, and having means for obtaining, from the server computer, the latest content data on the web relating to the URLs described in the distribution URL list and transmitting the data to the geostationary satellite; Means for receiving latest web content data of another server computer distributed from a geostationary satellite, provided for each server computer, wherein the geostationary satellite is a server computer transmitted by the transmission means. In a communication system in which a new content related to the web is distributed to another server computer by a point-to-multipoint method, at least one of the server computers includes the geostationary satellite. Complete web content data delivered from The communication system management server computer further includes means for sending a reception report to the communication system management server computer indicating that the content data has not been received, and the communication system management server computer completely receives the web content data based on the reception report. A communication system, further comprising: means for transmitting data not received to a server computer that did not receive the data.

2 9. The reception report is sent to the communication system management server via the Internet. And transmitting the data not received to the server computer that has not completely received the content data of the web via the Internet, in addition to the data transmitted to the computer. 28. The communication system according to item 8.

30. The reception report is transmitted to the communication system management server computer via the Internet, and based on the reception report, the non-received data is again transmitted to the geostationary satellite based on the reception report. 29. The apparatus according to claim 28, further comprising means for transmitting data to the server, thereby enabling the server computer to completely receive the content data of the web by transmitting the data again by the geostationary satellite. Communications system.

31. The communication system management server computer determines at least a data amount for the content data and a prediction regarding the frequency of access from the client of the server computer to the web to download the content data. Based on any one of the above, the system further includes means for enabling the distribution URL list to be edited, whereby new content data relating to the Web having the URL described in the distribution URL list as an address is generated. After that, regardless of whether or not the client has requested download of the content data, the web content of the URL described in this distribution URL list is transmitted to the geosynchronous satellite in advance, and the geosynchronous satellite receives To point server multi-point system Multicast data delivery is performed, and the transmitted data is cached in the cache server of each server computer. When a client of each server computer subsequently requests a download of the content data, the client computer transmits the data to the client server. 29. The communication system according to claim 28, wherein the communication system can be directly downloaded from a cache server of a server computer to which the server belongs.

32. The means for acquiring the latest content data and transmitting it to a geostationary satellite possessed by the communication system management server computer is described in the distribution URL list. 31. The system according to claim 31, further comprising: a patrol / automatic collecting means for periodically circulating the URL and automatically collecting the latest content data from the server computer; and a means for transmitting the latest content data to the geostationary satellite. Communication system.

33. The patrol / automatic collection means consists of web patrol application software constructed in the application layer, while the means for transmitting the latest content data to the geostationary satellite is multicast transmission constructed in the presentation layer. The communication system according to claim 32, comprising a library.

34. The communication system according to claim 33, wherein said web patrol application software starts as a daemon and continues to run until a system shutdown.

3 5. Each server computer has web push software built on the application layer to cache in the cache server, and multicast reception built on the presentation layer as a means to receive the latest content data on the web. The communication system according to claim 32, further comprising a library.

36. The communication system according to claim 35, wherein the web push software is started as a daemon and continues to be executed until a system shutdown occurs.

37. The communication system management server computer has a duplex configuration including a main system and a sub system, and a monitoring unit provided in the sub system monitors a process status table provided in the main system with a timer, The monitoring unit shuts down the main system and activates the patrol / automatic collection unit in the sub system when a failure is detected in the main system or when the sub system cannot communicate with the main system. The first-glance system according to claim 32, wherein

3 8. Connected to the master and slaves to own and manage the delivery URL list In addition, by providing a common server computer, it is possible to perform patrols based on the distribution URL list even when the main system is shut down and patrols are performed and the automatic collection means is activated. The communication system according to claim 37.

39. The means for editing the editable distribution URL list collects and analyzes information regarding the frequency of access to each web from the client on the server computer, and analyzes the URL to be included in the distribution URL list. 31. The communication system according to claim 31, comprising software for automatically collecting and analyzing access frequency information that enables the determination.

40. The software that automatically collects and analyzes the access frequency information obtains the access log information of each server computer, and integrates this access log information to determine the access frequency of each web on the Internet. 30. The communication system according to claim 39, wherein the communication system is software for determining a value to be reflected, and determining a URL to be included in the distribution URL list based on the value reflecting the access frequency.

4 1. The software that automatically collects and analyzes the access frequency information is based on the access frequency value of each web on the Internet included in the access log information of each server computer. 30. A software which performs a predetermined weighting, calculates an added value or an arithmetic average of the weighted values, and determines a URL to be described in the distribution URL list. A communication system as described.

4 2. The software that automatically collects and analyzes the access frequency information does not weight the access frequency value of each web on the Internet included in the access log information of each server computer. 30. The communication system according to claim 39, wherein the communication system is software for calculating an addition value or an arithmetic average value and determining a URL to be described in the distribution URL list.

4 3. The means for editing the editable distribution URL list is a new content. 32. The communication system according to claim 31, wherein the distribution URL list is automatically edited based only on the data amount for the data.

44. The means for editing the editable distribution URL list collects at least one of information on the amount of data for new content data and the frequency of access to each web from a client of the server computer, and 31. The communication system according to claim 31, comprising software for determining a URL to be included in the distribution URL list based on the evening analysis and editing the distribution URL list. .

45. The software should collect both the amount of data for the new content data and the frequency of access to each web from the client of the server computer, and enter the information in the distribution URL list based on the analysis of the operator. 46. The communication system according to claim 44, wherein the communication system is software for determining a URL and editing the distribution URL list.

46. The software collects both information on only the amount of data for new content data, determines the URL to be included in the distribution URL list based on the analysis of the operator, and can edit the distribution URL list 46. The communication system according to claim 44, wherein the communication system is software for reducing the time required for communication.

47. The software collects both information relating only to the prediction of the access frequency, determines the URL to be included in the distribution URL list based on the analysis of the operator, and enables the distribution URL list to be edited. The communication system according to claim 44, wherein the communication system is software.

48. URLs listed in the distribution URL list are URLs of websites that are linked to well-known portal sites predetermined by the operator and that are accessed frequently based on past access information on the Internet. Including 31. The communication system according to claim 31, wherein:

49. The URLs listed in the distribution URL list are the URLs of files that contain at least one of software, image data, audio data, and music data whose data volume exceeds a certain standard predetermined by the operator. 31. The communication system according to claim 31, wherein:

50. The patrol / transmission means may determine whether the URLs listed in the distribution URL list are not marked as cacheable in the HTTP header, the contents previously distributed by this communication system, and the cache expiration date. Content that has expired and that has the last update date of the previously delivered content and the last update date of the content that is currently being delivered coincides with the selection and control software to prevent transmission to the geostationary satellite. The communication system according to claim 1.

5 1. The patrol / transmission means specifies a URL distribution start time and enables scheduled distribution, and specifies only the top page in the URL and transmits hyperlinked content in the same site at once 31. The communication system according to claim 31, further comprising means for performing.

52. The server computer having a plurality of clients, the clients including any type of server computer forming a closed network connected to the Internet via the server computer. Item 31. The communication system according to item 1.

53. A plurality of cache servers installed in a fixed area of a geosynchronous satellite having a fixed area where data can be distributed, and having a cache server for owning and managing Internet content data on the Internet and for cashing the cache data In a communication method of performing a multicast data distribution by a point-to-multipoint method, the latest content data of the web received from individual clients of different server computers to another server computer via the geostationary satellite, Distribute web content data based on at least one of the amount of data for the content data and / or the frequency of access from the client of the server computer to the web for downloading the content data. By editing at least one distribution URL list that needs to be updated, new content data related to the Web having the URL described in the distribution URL list as an address is generated, Regardless of whether there is a download request or not, a web content data of the URL described in the distribution URL list is transmitted to the geostationary satellite in advance, multicast data is distributed, and the transmitted data is transmitted to each server computer. Cache in cache server Then, when a request for download of content data is issued from a client of each server computer after that, it is possible to download directly from the cache server of the server computer to which this client belongs. Characteristic communication method.

5 4. If at least one of the server computers has not completely received the content data of the web delivered from the geostationary satellite, a communication report to that effect is sent to the communication system management server computer via the Internet. The communication system management server computer transmits, via the Internet, the data not received to the server computer that has not completely received the web content data based on the reception report. The communication method according to claim 53.

55. If at least one of the server computers did not completely receive the web content data transmitted from the geostationary satellite, a communication report to that effect is sent to the communication system management server via Internet. The communication system management server computer transmits the data not received to the geostationary satellite again based on the reception report, so that the geostationary satellite distributes the data again. Content data 54. The communication method according to claim 53, wherein the communication can be completely received.

56. Using software, it is possible to collect and analyze information on the frequency of access to each web from the server computer client and determine the URL to be included in the distribution URL list. 54. The communication method according to claim 53, wherein collection and analysis of the access frequency information to be performed are automatically performed, and the distribution URL list is edited.

57. Obtain the access log information of each server computer, integrate this access port information, determine a value that reflects the frequency of access to each web on the Internet, and set a value that reflects this frequency of access. 57. The communication method according to claim 56, wherein a URL is determined to be included in the distribution URL list based on the URL.

58. The access frequency value of each web on the Internet included in the access log information of each server computer is weighted in advance for each server computer, and the sum of the weighted values or the arithmetic mean is calculated. 58. The communication method according to claim 57, wherein a URL is determined to be included in the distribution URL list.

59. The URL to be included in the distribution URL list is calculated without adding weight to the value of the access frequency of each web on the Internet included in the access log information of each server computer, and calculating the added value or the average value. The communication method according to claim 57, wherein the communication method is determined.

60. The communication method according to claim 53, wherein the editable distribution URL list is edited based only on a data amount for a new content data.

6 1. At least one of the information on the data volume for the new content data and the frequency of access to each web from the client of the server computer is collected, and the information is described in the distribution URL list based on the analysis of the operator. Determining a URL and editing the distribution URL list.

The communication method described in 53. .

62. Both the data amount for the new content data and the information on the frequency of access to each web from the client of the server computer are collected, and based on the analysis of the operator, the URL is described in the distribution URL list. The communication method according to claim 61, wherein the communication URL is determined and the distribution URL list is edited.

63. A method for collecting both information on only the data amount of new content data, determining a URL to be included in the distribution URL list based on an analysis of an operator, and editing the distribution URL list. 6 Communication method described in 1.

64. To collect both information relating only to the prediction of the access frequency, determine the URL to be included in the distribution URL list based on the analysis of the operation, and enable the distribution URL list to be edited. The communication method according to claim 61, wherein the communication method is software.

65. URLs listed in the distribution URL list are linked to well-known portal sites predetermined by the operator, and the access frequency is determined based on past access information on the Internet. 54. The communication method according to claim 53, comprising a URL of a high homepage.

66. The URL listed in the distribution URL list shall be the URL of a file containing at least one of software, image data, audio data, and music data whose data amount exceeds a certain standard predetermined by the operator. 54. The communication method according to claim 53, wherein:

67. Even if the URL is listed in the distribution URL list, content that is not marked as cacheable in the HTTP header, Content delivered by the system, content whose cache has expired, and content whose last update date of the previously delivered content matches the last update date of the content currently being delivered are not transmitted to the geostationary satellite. The communication method according to claim 53, wherein:

6 8. The delivery start time of the URL is specified to enable schedule delivery, only the top page is specified in the URL, and the hyperlinked content is transmitted collectively within the same site. The communication method described.

69. The server computer has a plurality of clients, the clients including any type of server computer forming a closed network connected to the Internet via the server computer. The communication method according to claim 53, characterized in that: